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The quest to build the tallest and most extravagant skyscrapers in the world is not without its share of setbacks. Since 2012, the UAE has seen around five spectacular skyscraper fires, including two this year — The Address Hotel in Dubai and Ajman One in Ajman. Often cigarette butts, shisha or barbecue grills were blamed as the primary cause of fire, but in all cases, fire spread rapidly because of the buildings’ cladding, consisting of aluminium and polyurethane composite panels.
While cladding can be made with fire-resistant material, experts say such material was not used before 2012 and was only made mandatory by new building regulations introduced in 2013.
”The old cladding used before 2013 is not necessarily hazardous, but it can be flammable under certain circumstances and, depending on a skyscraper’s design, may channel fires through windows into the interiors of buildings,” explains Phil Barry, founder of Britain’s CWB Fire Safety Consultants, which has experience with building construction and safety in Dubai.
After The Address hotel incident, Rashid Thani Al Matroushi, Director of Dubai Civil Defence, said the UAE Fire and Life Safety Code would be updated to prevent the use of cladding on buildings higher than nine storeys under certain conditions. Authorities also acknowledged that up to 20 per cent of buildings in the UAE may have flammable cladding.
In the wake of the blaze at The Torch, one of the tallest residential skyscrapers in the world that was ravaged by a fire in February last year, Dubai Civil Defence said it would be purchasing several jet packs and other technologies from New Zealand-based Martin Aircraft to be able to quickly respond to skyscraper fires, with delivery set for this year. Fire trucks would also be equipped with updated GPS systems to reach any location quicker.
The updated UAE Fire and Life Safety Code, on the other hand, has still not come into effect, although authorities say it should be out soon. Extensive testing of alternative cladding material, particularly on skyscrapers, and ongoing talks with developers and material manufacturers have been cited as among the reasons of the delay. The code is expected to include a stricter construction monitoring mechanism and a new section on liabilities in case of emergencies.
”With regards to recent fires on tall structures, strict action is needed to use fireproof and retardant materials in the buildings,” Hamza Ali, Dubai-based construction safety expert and senior specification consultant at Allegion, a global provider of security products and solutions for buildings, tells Property Weekly. ”The materials should be properly tested, certified and labelled by a third-party testing facility. The authorities having jurisdiction should make sure the manufacturers and suppliers of the building materials do not bypass the rules by using loopholes in the specification.
”The owners and contractors should not be allowed to change the specification of the building to save cost, use cheap materials or otherwise compromise the safety of the building and its occupants.”
Barry also says that nonflammable materials should be used in buildings at least 30m in height. ”The basic rule is that the outside of any building over 30m — which is as high as any fire ladder can reach — must be made of non-combustible materials,” says Barry, although he admits that a large number of buildings in the UAE do not meet the standard.
High-rise buildings also need to have a comprehensive crisis plan tailored for their structures. Skyscrapers present several unique challenges not found in low-rise buildings, such as longer egress times and distances, individual evacuation strategies, fire department accessibility, smoke movement and fire control. Tall buildings also need to evacuate a large number of persons at great vertical distances on stairs, which makes special certification processes for supertall structures necessary.
”A proper certification is needed for fire safety and allied services of the building like fire sprinklers, emergency lighting, emergency escape routes, fire escape doors and all related hardware,” says Hamza. ”Whatever the height of the tower, it should allow fast and easy evacuation. There should be safe floors for every few floors as you cannot expect occupants to climb down 70 to 80 floors in one go.
”The escape stairs have to be wide, well-lit and pressurised. The fire escape doors have to have well-lit signage and heavy-duty escape hardware for ease of egress.”
A well-thought-out safety system for super-tall skyscraper is also an issue for insurance companies. According to Allianz Global Corporate & Specialty, the insured values involved with super-tall buildings are constantly increasing. Allianz is lead insurer of buildings such as the Burj Khalifa, the upcoming Kingdom Tower in Saudi Arabia, Taipei 101 and Petronas Towers in Kuala Lumpur, and co-insurer of the new One World Trade Centre in New York and the tallest building in the UK, The Shard. The firm says today’s newest and largest buildings easily exceed $1 billion (Dh3.67 billion) in value, such as the Burj Khalifa. The Kingdom Tower has a total insured value of $1.5 billion.
Allianz cites resistance to earthquake or any seismic or natural catastrophes such as floods, as well as fire safety, quality of building materials and crisis and evacuation plans as crucial for skyscraper safety.
”If an event such as an earthquake or another natural hazard was to occur, it could obviously have a potential high impact,” says Clive Trencher, Senior Risk Consultant at Allianz. ”Fire risk in tall buildings, both during the construction and occupied phases, is a multiplied risk factor and represents a considerable challenge for designers and engineers. Evacuation of a building, which caters for multiple purposes like hotels, restaurants, residential areas, shopping centres and offices, is crucial especially considering the number of people to be evacuated within a short time.”
He adds that building owners must pay attention to the sprinkler systems, escape rooms and fire-resistant structures at an early stage of building’s design.
Source: Arno Maierbrugger, Special to Property Weekly